当我导入具有不同属性的CSV文件时：父级和学生。我收到一条错误消息：class Student < ActiveRecord::Base
belongs_to :parent
delegate :email,:name,:phone_number,to: :parent, allow_nil: true
def self.to_csv
attributes = %w{parent_id email phone_number first_name last_name age workshop interest registration_date email }
CSV.generate(headers: true) do |csv|
csv << attributes
all.each do |script|
csv << attributes.map{ |attr| script.send(attr) }
end
end
end
def self.import(file)
spreadsheet = open_spreadsheet(file)
header=spreadsheet.row(1)
(2..spreadsheet.last_row).each do |i|
row = Hash[[header,spreadsheet.row(i)].transpose]
spreadsheet.each do |row|
student = find_by_id(row["id"])|| new
parent = student.parent || student.build_parent
student.attributes = row.slice(*STUDENT_ATTRIBUTES)
parent.attributes = row.slice(*PARENT_ATTRIBUTES)
student.save!
parent.save!
end
end
end
def self.open_spreadsheet(file)
case File.extname(file.original_filename)
when ".csv" then Roo::CSV.new(file.path)
when ".xls" then Roo::CSV.new(file.path)
when ".xlsx" then Roo::CSV.new(file.path)
else raise "Unknown file type: #{file.original_filename}"
end
end
end
。如何在学生属性中导入父属性。任何帮助表示赞赏。
def import
Student.import(params[:file])
redirect_to root_url, notice: "student imported."
end
end
学生管理员：
<h2>Import Students</h2>
<%= form_tag import_students_path, multipart: true do %>
<%= file_field_tag :file %>
<%= submit_tag "Import" %>
<% end %>
查看文件夹：
app/models/student.rb:85:in `[]'
app/models/student.rb:85:in `block (2 levels) in import'
roo (2.3.2) lib/roo/base.rb:360:in `block in each'
roo (2.3.2) lib/roo/base.rb:359:in `upto'
roo (2.3.2) lib/roo/base.rb:359:in `each'
app/models/student.rb:84:in `block in import'
activesupport (4.2.1) lib/active_support/core_ext/range/each.rb:7:in `each'
activesupport (4.2.1) lib/active_support/core_ext/range/each.rb:7:in `each_with_time_with_zone'
app/models/student.rb:70:in `import'
app/controllers/students_controller.rb:15:in `import'
actionpack (4.2.1) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (4.2.1) lib/abstract_controller/base.rb:198:in `process_action'
actionpack (4.2.1) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (4.2.1) lib/abstract_controller/callbacks.rb:20:in `block in process_action'
activesupport (4.2.1) lib/active_support/callbacks.rb:117:in `call'
activesupport (4.2.1) lib/active_support/callbacks.rb:117:in `call'
activesupport (4.2.1) lib/active_support/callbacks.rb:555:in `block (2 levels) in compile'
activesupport (4.2.1) lib/active_support/callbacks.rb:505:in `call'
activesupport (4.2.1) lib/active_support/callbacks.rb:505:in `call'
activesupport (4.2.1) lib/active_support/callbacks.rb:92:in `_run_callbacks'
activesupport (4.2.1) lib/active_support/callbacks.rb:776:in `_run_process_action_callbacks'
activesupport (4.2.1) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (4.2.1) lib/abstract_controller/callbacks.rb:19:in `process_action'
actionpack (4.2.1) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (4.2.1) lib/action_controller/metal/instrumentation.rb:32:in `block in process_action'
activesupport (4.2.1) lib/active_support/notifications.rb:164:in `block in instrument'
activesupport (4.2.1) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.2.1) lib/active_support/notifications.rb:164:in `instrument'
actionpack (4.2.1) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
actionpack (4.2.1) lib/action_controller/metal/params_wrapper.rb:250:in `process_action'
activerecord (4.2.1) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (4.2.1) lib/abstract_controller/base.rb:137:in `process'
actionview (4.2.1) lib/action_view/rendering.rb:30:in `process'
actionpack (4.2.1) lib/action_controller/metal.rb:196:in `dispatch'
actionpack (4.2.1) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
actionpack (4.2.1) lib/action_controller/metal.rb:237:in `block in action'
actionpack (4.2.1) lib/action_dispatch/routing/route_set.rb:74:in `call'
actionpack (4.2.1) lib/action_dispatch/routing/route_set.rb:74:in `dispatch'
actionpack (4.2.1) lib/action_dispatch/routing/route_set.rb:43:in `serve'
actionpack (4.2.1) lib/action_dispatch/journey/router.rb:43:in `block in serve'
actionpack (4.2.1) lib/action_dispatch/journey/router.rb:30:in `each'
actionpack (4.2.1) lib/action_dispatch/journey/router.rb:30:in `serve'
actionpack (4.2.1) lib/action_dispatch/routing/route_set.rb:819:in `call'
rack (1.6.4) lib/rack/etag.rb:24:in `call'
rack (1.6.4) lib/rack/conditionalget.rb:38:in `call'
rack (1.6.4) lib/rack/head.rb:13:in `call'
actionpack (4.2.1) lib/action_dispatch/middleware/params_parser.rb:27:in `call'
actionpack (4.2.1) lib/action_dispatch/middleware/flash.rb:260:in `call'
rack (1.6.4) lib/rack/session/abstract/id.rb:225:in `context'
rack (1.6.4) lib/rack/session/abstract/id.rb:220:in `call'
actionpack (4.2.1) lib/action_dispatch/middleware/cookies.rb:560:in `call'
activerecord (4.2.1) lib/active_record/query_cache.rb:36:in `call'
activerecord (4.2.1) lib/active_record/connection_adapters/abstract/connection_pool.rb:649:in `call'
activerecord (4.2.1) lib/active_record/migration.rb:378:in `call'
actionpack (4.2.1) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.2.1) lib/active_support/callbacks.rb:88:in `call'
activesupport (4.2.1) lib/active_support/callbacks.rb:88:in `_run_callbacks'
activesupport (4.2.1) lib/active_support/callbacks.rb:776:in `_run_call_callbacks'
activesupport (4.2.1) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (4.2.1) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.2.1) lib/action_dispatch/middleware/reloader.rb:73:in `call'
actionpack (4.2.1) lib/action_dispatch/middleware/remote_ip.rb:78:in `call'
actionpack (4.2.1) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
web-console (2.3.0) lib/web_console/middleware.rb:20:in `block in call'
web-console (2.3.0) lib/web_console/middleware.rb:18:in `catch'
web-console (2.3.0) lib/web_console/middleware.rb:18:in `call'
actionpack (4.2.1) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
railties (4.2.1) lib/rails/rack/logger.rb:38:in `call_app'
railties (4.2.1) lib/rails/rack/logger.rb:20:in `block in call'
activesupport (4.2.1) lib/active_support/tagged_logging.rb:68:in `block in tagged'
activesupport (4.2.1) lib/active_support/tagged_logging.rb:26:in `tagged'
activesupport (4.2.1) lib/active_support/tagged_logging.rb:68:in `tagged'
railties (4.2.1) lib/rails/rack/logger.rb:20:in `call'
actionpack (4.2.1) lib/action_dispatch/middleware/request_id.rb:21:in `call'
rack (1.6.4) lib/rack/methodoverride.rb:22:in `call'
rack (1.6.4) lib/rack/runtime.rb:18:in `call'
activesupport (4.2.1) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
rack (1.6.4) lib/rack/lock.rb:17:in `call'
actionpack (4.2.1) lib/action_dispatch/middleware/static.rb:113:in `call'
rack (1.6.4) lib/rack/sendfile.rb:113:in `call'
railties (4.2.1) lib/rails/engine.rb:518:in `call'
railties (4.2.1) lib/rails/application.rb:164:in `call'
rack (1.6.4) lib/rack/lock.rb:17:in `call'
rack (1.6.4) lib/rack/content_length.rb:15:in `call'
rack (1.6.4) lib/rack/handler/webrick.rb:88:in `service'
/home/vagrant/.rvm/rubies/ruby-2.0.0-p643/lib/ruby/2.0.0/webrick/httpserver.rb:138:in `service'
/home/vagrant/.rvm/rubies/ruby-2.0.0-p643/lib/ruby/2.0.0/webrick/httpserver.rb:94:in `run'
/home/vagrant/.rvm/rubies/ruby-2.0.0-p643/lib/ruby/2.0.0/webrick/server.rb:295:in `block in start_thread'
这里是完整的跟踪错误：
Gradle 'MyProject' project refresh failed
Error:Cause: invalid LOC header (bad signature)